Abstract: Hyperkinetic children are identified as a “population-at risk” upon admission to kindergarten. The etiology of hyperkinetic behavior is controversial. “Organic driveness,” “hyperkinetic behavior disorder,” “postencephalitic behavior,” “brain damage with behavioral and conceptual deficit,” “Strauss syndrome,” have all been used to label essentially similar symptom constellations. Bypassing the area of controversy, a study is reported that demonstrates that children who were identified as “hyperkinetic” (using behavioral criteria developed in an earlier study) were (1) absent from school more frequently, and (2) did remarkably less well on standardized tests of school readiness than their peers rated “nonhyperkinetic.” The implications are discussed and suggestions made for the development of intervention programs .